I found that bug on my server, and first i didn't even known how i did it, so:
First you have to get an pet, and use eyes of the beast
Now if you go and attack with wing clip, it won't have any cooldown, i don't know why it happens, but anyway is good for the one hit kill things..
The problem is that it consumes mana but anyway is good enough for 1 hit kills with blinkstrike, flurry axe, etc :P
Sorry if repost, anyway enjoy it:P
LE: Just imagine what would happen , if you would put Raptor Strike instead wing clip with Wpe